title: The syntheses, structures and properties of three new lanthanoid thioarsenates: the only example of thioarsenate acting as a ligand to a lanthanide complex.
abstract: Three new lanthanoid thioarsenates [Eu(en)3(η²-AsS₄)] (1, en = ethylenediamine), [Er(teta)(en)(η²-AsS₄)] (2, teta = triethylenetetramine) and [La₂(tepa)₂(μ-η¹,η³-AsS₃)₂] (3, tepa = tetraethylenepentamine) have been solvothermally synthesized and structurally characterized. In compounds 1 and 2, the tetrathioarsenate [AsS₄]³⁻ anions act as η²-AsS₄ chelating ligands to the lanthanide complexes [Eu(en)₃]³⁺/[Er(teta)(en)]³⁺, leading to neutral molecules [Eu(en)₃(η²-AsS₄)]/[Er(teta)(en)(η²-AsS₄)], whereas the [AsS₃]³⁻ anion in compound 3 acts as a μ-η¹,η³-AsS₃ tetradentate bridging ligand to link [La(tepa)]³⁺ ions into neutral centrosymmetric [La₂(tepa)₂(μ-η¹,η³-AsS₃)₂] moieties, where a new coordination mode of μ-η¹,η³-AsS₃ is observed for the [AsS₃]³⁻ ligand. Compounds 1-3 are the only examples of solvothermally synthesized thioarsenates where the [AsS₄]³⁻/[AsS₃]³⁻ anions act as ligands in the lanthanide complex. Compound 1 exhibits a fluorescence emission at room temperature. Density functional theory calculations for compounds 2 and 3 also have been performed, and the absorption edges of compounds 1-3 have been investigated by UV-vis spectroscopy.
authors.affiliation: College of Chemistry, Chongqing Normal University, Chongqing, 401331, PR China. jianzhou888888@163.com
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.forename: Xing
authors.initials: X
authors.lastname: Liu
authors.forename: Rong
authors.initials: R
authors.lastname: Li
authors.forename: Litao
authors.initials: L
authors.lastname: An
authors.forename: Feilong
authors.initials: F
authors.lastname: Hu
authors.forename: Rong
authors.initials: R
authors.lastname: Chen
authors.forename: Yuanchun
authors.initials: Y
authors.lastname: Wei